Quantitative digital and palmar dermatoglyphics among Sardinian linguistic groups.

Discriminant analyses of 23 digital and 15 palmar quantitative dermatoglyphic variables of 1364 Sardinians, 689 males and 675 females, were performed to identify biological relationships among five Sardinian linguistic groups of both sexes. By various subsets of dermatoglyphic variables (23 and 20 digital, 15 and 14 palmar, 4 summary traits) MANOVA revealed high intergroup heterogeneity among the groups of both sexes and within each sex. In the latter case the males are an exception when 15 and 14 (MLI removed) palmar variables are used. Standard discriminant analysis of the 23 digital variables, i.e. the radial and ulnar ridge counts on each of the 10 fingers plus total finger ridge count (TFRC), absolute finger ridge count (AFRC) and pattern intensity (PI), resulted in imperfect separation of males and females and an unclear picture of the biological relationships among the groups. In contrast, standard discriminant analysis of 20 digital variables (TFRC, AFRC and PI were removed from the analysis) resulted in separation of the sexes and a pattern of relationships among the populations consistent with their ethno-historical backgrounds. Standard discriminant analysis of 15 palmar dermatoglyphic variables failed to provide separation of the sexes and produced a pattern of relationships in disagreement with both the linguistic and ethno-historical backgrounds, even removing MLI (Main Line Index). Standard discriminant analysis of 4 summary dermatoglyphic variables (TFRC, AFRC, PI and MLI) yielded imperfect separation of males and females and an unclear pattern of relationships. By stepwise discriminant analysis with p < or = 0.01 as F-to-enter and p < or = 0.05 as F-to-remove, only 4 of the 38 digital and palmar variables were in the model (URC R5, RRC L5, RRC R5, URC R4). The pattern of inter-population biological relationships was conceptually similar to the one produced by the 20 digital variables. It showed a clear separation of the Gallurian group (both males and females), which speaks an Italian dialect. The properly Sardinian linguistic groups (Campidanian and Logudorian), the Sassarian group (which speaks an Italian dialect) and the Alghero group (which speaks Catalan) were close to one another. This picture agrees with the ethno-historical background rather than with the linguistic one.

Inter-sex and intra-sex differences in quantitative digital dermatoglyphics of Sardinian-speaking groups.

In this study, we analysed inter-sex differences within two linguistic groups from the Sardinian linguistic area and intra-sex differences between the two groups by means of 41 quantitative digital dermatoglyphic variables: 20 digital dermatoglyphic traits (radial and ulnar ridge counts on each of the 10 fingers), 15 digital dermatoglyphic directional asymmetry variables, total finger ridge count, bilateral summed radial and ulnar finger ridge counts, an index of asymmetry between homologous fingers, and two indices of intra-individual diversity of finger ridge counts. The comparisons between males and females within the same linguistic groups and between the males of the two groups and the females of the two groups were carried out with the Mann-Whitney test at a prefixed level of alpha = 0.05, using the Bonferroni correction for multiple comparisons. The results indicate a strong similarity of the two linguistic groups in the inter-sex differences, whereas there are no significant differences between them for either males or females. The similar pattern of sexual dimorphism and the homogeneity of the males and females of the two groups suggest a common genetic matrix of these Sardinian-speaking groups.